A tert-butyl/cyano substituted (1,2,3,5-dithiadiazolyl) benzene and η2 π complexes with CpCr(CO)2

A rational synthesis for 5-tert-butyl-3-cyano-1-(1,2,3,5-dithiadiazolyl) benzene; which was first observed from thermal cleavage of the bis-dithiadiazolyl, has been developed. Voltammetry and electron paramagnetic resonance (EPR) spectra for this radical are reported and its X-ray structure is described. Despite the bulky Bu-t substituent, the cyano supramolecular synthon is still able to maintain links to a single neighbouring sulfur atom of the S-2 unit, as previously observed in cyano-substituted dithiadiazolyls. In the eta(2) complex with CpCr(CO)(2), no such interactions are observed; the nitrile group forms a centrosymmetric dimer through weak contacts with the para H atom on the aryl ring of the partner molecule. This behaviour is contrasted to similar complexes of less bulky dithiadiazolyls, where intermolecular interactions are retained in the crystalline lattice. (c) 2006 Elsevier B.V. All rights reserved.